Drawing board clamp



Sept. 24; 1935. s. TINDAL DRAWING BOARD CLAMP Original Filed Jan. 25, 1933 Evan-0Q STEP/{Eu 77 N0 4 L.

IVTTORNEY Patented Sept. 24, 1935 UNITED STATES PATNT orries Application January 25, 1933, Serial No. 653,530.

Renewed April 26, 1935. In Great Britain February 1, 1932 1 Claim.

This invention has relation to a drawing board clamp and has essentially for its object to provide a clamping device attached to a drawing board for fastening the paper without use of pins 5 or adhesive.

The invention further includes those novel details of construction, combination and arrangement of parts, which will be fully described reference being had to the accompanying drawing,

in which:

Fig. 1 is a plan View of a drawing board illustrating the clamping device in position in accordance with the subject matter of my invention;

Fig. 2 is a side elevation of the same;

Fig. 3 is an enlarged perspective view of the clamping device.

In accordance with my invention the drawing board is fitted with a clamp A, which lies across the surface of the board B, close to its top edge 20 as shown in Fig. 1 in the accompanying drawing. The clamp is grooved along its under surface to a size which fits accurately over a guide strip C, which is fitted tothe board and fixed as shown in Fig. 2. Through the board and strip 25 and clamp pass screw bolts, and the whole is tightened with finger or winged nuts D. The front edge of the under surface of the clamp A presses against an inserted sheet of drawing paper and holds it tightly to the board.

When the drawing sheet is inserted it comes in contact with the guide strip 0, and this being at right angles to the edge of the board 13, immediately determines the position of the drawing sheet. At this stage the said guide strip is hidden, but view holes F are made in the clamp A, exposing parts of strip C, toenable the user of the board to see if the drawing paper is resting wholly against the edge of the said guide strip as illustrated in Fig. 3. When this has been ascertained the finger nuts D are tightened up, making it impossible for the drawing paper to alter its position. Steel springs are fitted between strip 0 and clamp A, which throw the said clamp clear of the drawing paper immediately the nuts are released.

A groove G is formed in the member A for the purpose of receiving pencils and other drawing instruments.

Having now particularly described my inven- 

